Fuel injector for internal-combustion engines



l 625,606 April 19 1927. R" HILDEBRAND Q FUEL INJECTOR FOR INTERNAL COMBUSTION ENGINES Filed Maron 22. 192s Bywmmw the combustion chamber.

Patented pr. 19, i927.

UNITED stares l-Edd PATENT FFC.

REINHARD HILDEBRAND, 0F WEBSTER GROVES,` MISSOURI, .ASSIGNOR` TO FULTOlr IRON WORKS COMPANY, OF ST. LOUIS, MISSOURI, CORPORATION 0F DELAWARE.

FUEL INJECTOR FOR INTERNAL-COMBS'TON ENGINES.

Application filed March 22,

This invention relates to improvements in fuel injectors particularly adapted for use in engines of the Diesel type wherein compressed air is employed to inject the fuel into the combustion chambers. In an engine of this type, the delivery of fuel is ordinarily regulated by a governorfand predetermined volumes of liquid fuel are forced into a nozzle from which they are discharged bycompressed air to the combustion chamber." Prior to this invention, measured charges of liquid fuel have been discharged across thepassageway in the nozzle so as to impinge against one ofthe side walls of the passageway, and owing to the tendency of the fuel to cling to the wall, it has not been effectively removed by the compressed air. As a consequence', the engine does not quickly respond to the action of the governor, and it .is liable to receive too much, or not enough, of the fuel.

It 1s to be understood that the fuel is injected during a very short period of time, and it is most desirable to discharge all of the fuel in the nozzle at each operation, so as to cause the predetermined charge to enter Obviously, this cannot be accomplished if a large percentage of the liquid fuel is clinging to one of the side walls of the passageway in the nozzle. In this event, some of the fuel will spread on the surface of the wall, instead of being instantly discharged to the combustion chamber.

jOne of the objects of the present invention is to produce a fuel injector from which each charge of fuel can be effectively discharged by compressed air, without leaving an uncertain amount `of the charge clinging to the interior of the nozzle. ln the preferred form of the invention, this is accom plished in a nozzle having a suitable passageway through which the compressed air is transmitted, and a fuel duct for the delivery of liquid fuel to said passageway, the discharge end of the fuel duct being directed toward the discharge end of the nozzle, so

that-the fuel will be readily ejected. This,

duct may be provided with blanchesm'the like, at its discharge end`,"s'o as to distribute the fuel in the interior of the nozzle, and these branches may terminate near an ordil nary atomizing device onto which the liquid fuel ,is discharged and distributed, to effecment of the invention.

1923. Serial No. 626,855.

tively receive the pressure of the compressed air.

Vith the foregoing and other objects in view, the invention comprlses `the novel construction, combination and arrangement of parts' hereinafter more specifically described .and illustrated in the accompanyingy draw- Vbeding the features of this invention, showing portions vof the cylinder head to which the nozzle is secured.

Fig. H is a side elevation of the tube having channels for the distribution of the liquid fuel.

Fig. Hl is a section on the line llllll in Fig. l.

The cylinder head comprises upper and lower walls l and 2 separated from each other to provide aY spacefor the cooling.

medium. rlhe nozzle comprises a tubular housing 3 provided at its lower end with a valve seat 4 and a discharge tip 5 secured to the member 4 by means of a threaded ring 6, the latter beingscrewed onto meniber 4 and provided with an inturned flange engaging a iange on the member 4. A. sleeve 7, surrounding the tubular member 3, is seated in the lower Wall 2 of the cylinder head, the upper end of this sleeve being extended into an opening 8 in the upper -wall 1 and engaged by a threaded ring 9 screwed into said opening. The sleeve 7, mounted in this manner, is intended to prevent leakage of water at the openings in which the nozzle is secured. A

L A .needle valve 10, extending from the upper end of the nozzle, is provided 'at its lower end with al tapered facell adapted .to engage a correspondingly I tapered face in the valve seat member 4. 12 designates a tubular guide in which the valve is mounted, .and 13 is a stuffing box at they upper end ofv said guide. A ange 14, extending from the lower portion of the stung box, lies between' a clamping member 15 and the upper end of the tubular housing 3, said upperv j end being enlarged to receive studs 16 which are screwed into the cylinder head and extended upwardly through the clamping member` 15 to receive nuts 17. The downward pressure of nuts 17 is transmitted through clamping member 15 and flange lll to the tubular member 3, so as to force the valve seat member t onto a gasket 18 in the wall 2.

A tube 19 is surrounded by and closely fitted to the inner face of the tubular housing 3, and this tube has a tapered lower end engaging a correspondingly tapered portion of the housing.` 2() designates a threaded ring screwed into the upper end of housing 3 and engaging the upper end of tube 19 so as to firmly force its tapered lower end onto the corresponding seat in the housing 3. A series of openings 21, formed in the upper end of tube 19, are in free communication with a passageway 22 providing an inlet for compressed air. rIhe air flowing from passagewa'y 22 flows through the openings 21 to the interior of tube 19, and thence downwardly to the discharge end of the nozzle, as will be hereafter described.

23 designates a passageway formed in the enlarged upper end of housing 3 to provide for the admission of liquid fuel. This passageway terminates at the inner face of tubula'r member 3. The fuel-distributing passageways are formed partly by the inner face of tubular member 3 and partly by channels in the outer face oftube 19, the latter being closely fitted to said inner face.

Channels 24 (Figs. I and II) diverge from the fuel inlet 23 to the ytapered lower portion of tube 19, and these channels have diverging branches 24 extending to the lower edge of said tapered portion. The lower ends of the `main channels 24 are at diametrically opposite points in the tube 19, and the branches 24: terminate at four equidistant points in the lower end of the tube, as shown most clearly by Fig. IIL The stream of liquid fuel is'thus divided and distributed through ducts having their discharge ends directed toward the discharge end of the nozzle. The streams of fuel issuing from the ducts, or channels 24', are discharged in a direction conforming approximately to the direction of the compressed air flowing through the nozzle, and the liquid fuel will i be effectively discharged with the air.

A series of atomizing plates, or rings 25, rest upon a cone 26 seated in the tapered opening in member 4, said cone having peripheral slots 27 through which the mixture of air and liquid fuel is conducted, and the plates 25 are provided with small perforations forming passageways for the fuel and a'ir. This atomizing device surrounds the lower end of the tubular guide 12 and lies ifeeaeoe the top face of the atomizing elements 25,

and the liquid fuel is distributed on this top face where it can be effectively acted upon by the compressed air and readily discharged from the nozzle.

I claim:

1. In a fuel injector for internal combustion engines, a tubular housing having a fuel inlet, an air inlet and an outlet for the discharge of aeir and liquid fuel, a tube sur rounded by and closely fitted to the inner face of said housing, said tube having a tapered end engaging a correspondingly tapered portion of said housing, a valve extending through said tube and seated in sa'id outlet to control the discharge therefrom, said air inlet being in communication with said tube to provide for the delivery of co1npressed air therethrough, the outer face of said tube having a channel communicating with said fuel inlet and provided with discharge branches in said tapered end, and said discharge branches being directed toward said outlet to provide for the discharge of streams of liquid fuel in approximately the direction of iow of the com'- pressed air.

2. In a. fuel injector for internal combustion engines, a tubular housing having a fuel inlet, an air inlet and an outlet for the discharge of air and liquid fuel, a tube surrounded by and closely fitted to the inner face of said housing, said tube having a tapered end engaging a correspondingly tapered portion of said housing, a valve extending through safid tube and seated in said outlet to control the discharge therefrom, said air inlet being in communication with said tube to provide for the delivery of compressed air therethrough, a fuelatomizing device between said outlet and the tapered end of said tube, the outer face of said tube being provided with channels diverging from said fuel inlet and having diverging discharge branches in said tapered end to provide for distribution of the liquid fuel, and said discharge branches being directed toward said fuel-atomizing device so as to discharge the fuel in a direction conforming approximately to the direction of the coinpressed air.

In testimony that I claim the foregoing I hereunto affix my signature.

REINHARD HILDEBRAND. 

